Odd Man Out

All except Pink are colours of the spectrum. The seven colours of the spectrum are – Violet, Indigo, Blue, Green, Yellow, Orange, Red.

626-1 = 625 = 25². 962-1 = 961 = 31². 1090-1 = 1089 = 33². But, 841-1 = 840 (not a perfect square). Otherwise, 841 is a perfect square of 29, other are not a perfect square.

In all other groups, the first and second as well as the third and forth letters are consecutive.

In all the other numbers, the sum of the first two digits is equal to the third digit.

In all other pairs, first number is 35 more than the second.

This is the only group containing the four consecutive letters in the correct alphabetical order.

In all other pairs, the difference between the two numbers is a multiple of 9.

All except Large are general physical properties of matter.

Sharp is different from others.

In all other pairs, first is a product made from the second.